U.S. Pat. No. 5,696,182 relates to an ink comprising water, a water-soluble organic solvent, a coloring material and a water-soluble oligomer.
U.S. Pat. No. 7,176,248 relates to a smear resistant ink jet ink using an aqueous carrier, a urethane dispersion as binder, and self-dispersing pigments.
US20040085419 relates to an ink jet ink comprising pigment, water optionally with water-miscible co-solvent, and a polyurethane of a specific formula.
US H2113H1 relates to a process for the preparation of an ink which comprises mixing an ink vehicle, a colorant and a polyurethane resin emulsion.
US 2005/0182154 discloses ink jet inks containing crosslinked polyurethanes.